TITLE: Cadence — release intelligence for teams that ship on purpose PROMPT: Build a single self-contained HTML page: a minimal, premium SaaS landing page for a fictional product called Cadence. Palette #ffffff paper, #0f172a ink, #6366f1 indigo, #a5b4fc soft, #f1f5f9 panel, with a full dark theme (paper #0b1120, ink #e8eefb, panel #141d33) toggled by a data-theme attribute on and CSS custom properties. A fixed, pointer-events-none gradient mesh sits behind everything: four radial gradients in indigo and soft violet on an inset -25% layer, drifting with a 34s alternate transform keyframe (no blur filter). Content shell max-width 1140px. A sticky nav that gains a translucent background and hairline border past 12px scroll (rAF-throttled), with a mono uppercase link row and a sun icon button. Hero: eyebrow pill, a clamp(34px,5.6vw,68px) 700 headline with the word "cadence" in an indigo-to-soft background-clip gradient, lede, two CTAs (the primary has an ::after gradient sweep that translates on hover) and a mono meta line. Beside it a pure-CSS product mock: a browser chrome bar, a 118px sidebar of mono nav items, a 14-bar chart whose bars keep their full inline height and only pulse scaleY with staggered delays, and a three-row metric list. Then a mono text logo strip, three feature cards with inline stroke SVG icons that lift on hover, a five-item FAQ accordion animated with grid-template-rows 0fr to 1fr, a single wide pricing card split into plan and inclusions halves with a monthly/yearly toggle that tweens the price number through rAF, and a four-column footer. Section reveals use IntersectionObserver but animate transform translateY(28px) to 0 only - never opacity - so a frozen render shows the complete page. Labels use ui-monospace uppercase with wide tracking. Reduced motion disables mesh drift, float, bar pulse and reveals. No external assets and no external references of any kind. DESCRIPTION: A calm, confident landing page for a fictional release-intelligence product. Soft indigo gradient mesh drifts behind crisp tight-tracked type; a CSS-only product mock tilts in space and floats beside the headline; feature cards, an easing accordion and a single wide pricing card carry the argument without a single image. A theme toggle flips the whole page to a deep navy dark mode, and the pricing toggle counts the price down. TECHNIQUES: CSS gradient mesh built from multiple radial gradients on a transformed fixed layer; CSS-variable theming with a data-theme attribute; background-clip text gradient; ::after gradient sweep on the primary CTA; pure-CSS product mock with a staggered scaleY bar pulse; grid-template-rows 0fr/1fr accordion; IntersectionObserver reveals restricted to transform for frozen-render safety; rAF-tweened pricing numbers; sticky nav state toggled in a rAF-throttled scroll handler. INTERACTION: Click a FAQ question to expand it (others close, the plus icon rotates and collapses); switch Monthly / Yearly and the price counts between 29 and 23 while the billing note changes; click the sun icon to flip light and dark themes; hover the primary CTA to run the gradient sweep; the nav links smooth-scroll to Features, FAQ and Pricing and the nav gains a blurred background once the page scrolls; feature cards lift on hover; the mesh drifts and the product mock floats.